Phthalocyanine mixed crystal and electrophotographic photoreceptor containing the same

Abstract

A phthalocyanine mixed crystal comprising a halogenated indium phthalocyanine and a halogenated gallium phthalocyanine and an electrophotographic photoreceptor containing the phthalocyanine mixed crystal. The phthalocyanine mixed crystal is a charge generating material which provides an electrophotographic photoreceptor excellent in sensitivity, stability on repeated use, and environmental stability.

What is claimed is: 
     
       1. A phthalocyanine mixed crystal comprising a halogenated indium phthalocyanine and a halogenated gallium phthalocyanine. 
     
     
       2. A phthalocyanine mixed crystal as claimed in claim 1, wherein said mixed crystal has distinct X-ray diffraction peaks at Bragg angle (2θ±0.2°) of 7.0°, 7.4°, 17.4°, 23.7°, and 27.0°. 
     
     
       3. A phthalocyanine mixed crystal as claimed in claim 1, wherein said mixed crystal has distinct X-ray diffraction peaks at Bragg angles (2θ±0.2°) of 7.4°, 16.7°, 25.4°, and 28.1°. 
     
     
       4. A phthalocyanine mixed crystal as claimed in claim 1, wherein said halogenated indium phthalocyanine is chloroindium phthalocyanine and said halogenated gallium phthalocyanine is chlorogallium phthalocyanine. 
     
     
       5. A phthalocyanine mixed crystal as claimed in claim 1, comprising a chloroindium phthalocyanine and a chlorogallium phthalocyanine and having distinct X-ray diffraction peaks at Bragg angle (2θ±0.2°) of 7.0°, 7.4°, 17.4°, 23.7° and 27.0° or at Bragg angle (2θ±0.2°) of 7.4°, 16.7°, 25.4° and 28.1°, and wherein said mixed crystal comprises chloroindium phthalocyanine and chlorogallium phthalocyanine in a weight ratio of from 30/70 to 70/30. 
     
     
       6. A phthalocyanine mixed crystal as claimed in claim 5, wherein said mixed crystal comprises chloroindium phthalocyanine and chlorogallium phthalocyanine in a weight ratio of from 40/60 to 60/40. 
     
     
       7. A method of making a phthalocyanine mixed crystal comprising the steps of: (a) mixing a halogenated indium phthalocyanine and a halogenated gallium phthalocyanine;   (b) grinding said mixture to an amorphous composition;   (c) treating said amorphous composition with an organic solvent; and   (d) recovering said phthalocyanine mixed crystal from said organic solvent.   
     
     
       8. A method as claimed in claim 7, wherein step (a) comprises mixing a crystalline halogenated indium phthalocyanine and a crystalline halogenated gallium phthalocyanine. 
     
     
       9. A method as claimed in claim 7, wherein said step (d) comprises filtering said treated mixture and recovering said phthalocyanine mixed crystal as a filtrate. 
     
     
       10. A method as claimed in claim 7, wherein said organic solvent comprises a solvent selected from the group consisting of halogenated hydrocarbons, aromatic hydrocarbons, alcohols, ketones, acetic esters, aliphatic hydrocarbons and ethers. 
     
     
       11. A method as claimed in claim 7, wherein said organic solvent comprises a solvent selected from the group consisting of methylene chloride, chloroform, toluene, benzene, chlorobenzene, methanol, ethanol, acetone, methylethyl ketone, ethyl acetate, butyl acetate, hexane, octane, diethyl ether, dioxane, tetrahydrofuran, ethylene glycol, dimethylformamide, mixtures of said solvents and mixtures of said solvents and water.